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This action-packed series for fans of the Treasure Hunters books continues with more historical mystery and interactive puzzles.

Middle school geniuses Sam, Martina, and Theo head to Glacier National Park to find the second of seven artifacts—keys that unlock a secret weapon left by the Founding Fathers. The clues here lead them toward Thomas Jefferson’s key, the Eagle’s Quill, at a Montana ranch. But dangerous Gideon Arnold is hot on their trail. He takes their chaperone and the ranch owners hostage until the kids deliver the key. Can Sam, Martina, and Theo, with the help of rancher girl Abby, find the quill before it's too late? They enter the wilderness to solve riddles and escape traps that protect the quill… but if they find it, can they keep it away from Arnold?

In this fast-paced adventure full of interactive puzzles, the kids and readers must use their wits to save our nation by uncovering its greatest secrets.